This invention relates generally to computer controlled systems and particularly to a system for providing a selected input from a plurality of inputs to the computer of such a system.
Typically the commands to a computer controlled system are supplied from a keyboard having a plurality of keys each of which places a particular command into the computer. The operator depresses the appropriate key and the computer receives the command.
An example of such a system is a computer controlled lighthouse which is used to expose the black matrix material on the inside surface of a color kinescope faceplate panel. In applying the black matrix to such a panel, a photosensitive is applied to the inside of the faceplate and a shadow mask is inserted into the panel. Intense light from the lighthouse lamp passes through the apertures in the shadow mask to expose portions of the photosensitive material. The shadow mask is then removed from the panel and the unexposed material washed away leaving a series of lines which are used to form the black matrix. Tubes vary in size and type, and shadow masks, therefore, have different light transmission capabilities. The required light exposure of the photosensitive material, therefore, must be set into the computer controlled lighthouse for each shadow mask. Shadow masks typically are grouped into categories in accordance with their light transmission capability. These categories are called cell sizes. Before the exposure of a panel, the cell size of the shadow mask is set into the computer to assure the proper exposure. Accordingly, there is a need for a system which permits the input of the particular cell size by momentarily closing a single switch within a set of switches provided on the panel of a system control computer.
The instant invention fulfills this requirement by the provision of a system for inputting a selected one of a plurality of commands to a computer by the closing of a single switch available on the panel of a computer.